Box blank holding device in a box-making machine

Abstract

A box blank holding device for a box-making machine has a main body, a driving rack and a motor mechanism for reciprocally moving the driving rack relative to the main body. A transmission shaft is rotatably supported on the main body, the transmission shaft having a pair of pinions, and one of the pinions being in meshing engagement with the driving rack. A pair of holding-member actuating racks are disposed in meshing engagement with the other pinion. Each of the holding-member actuating racks has a holding member pivotally mounted thereto on an end thereof. Each of the holding members also has a roller thereon. The rollers are guided in respective guide grooves provided on the main body for guiding the holding members between projecting and retracted positions for holding and releasing a stack of box blanks. By using a fluid cylinder as the motor mechanism, the holding force on a stack of box blanks can be predetermined.

I claim: 
     
       1. A box blank holding device for a box-making machine, comprising: a main body;   a driving rack;   motor means for reciprocally moving said driving rack relative to said main body;   a transmission shaft rotatably supported on said main body, said transmission shaft having a pair of pinions, one of said pinions being in meshing engagement with said driving rack;   a pair of holding-member actuating racks disposed in meshing engagement with the other said pinion;   each said holding-member actuating rack having a holding member pivotally mounted on an end thereof, whereby said holding members are movable with said holding-member actuating racks, said holding-member actuating racks being moved by said motor means reciprocally moving said driving rack to turn said one of said pinions, thus turning said other of said pinions and moving said holding-member actuating racks; and   means for causing said holding members to move between a projecting position and a retracted position, said means comprising projecting and retracting guide grooves on said main body and rollers on said holding members for engagement with said guide grooves.   
     
     
       2. The box blank device as set forth in claim 1, wherein: said means for causing comprises a pair of guide plates connected to said main body, each said guide plate defining a said guide groove.   
     
     
       3. The box blank holding device as set forth in claim 1, wherein: said guide grooves extend along a front face of said main body for guiding said holding members therealong in said projecting position, and turn substantially 90° at respective ends of said main body for guiding said holding members to said retracted position.   
     
     
       4. The box blank holding device as set forth in claim 3, wherein: said holding members are substantially flush with said front face in said retracted position.   
     
     
       5. The box blank holding device as set forth in claim 1, wherein: guide rails are mounted on a rear face of said main body;   said motor means is a fluid cylinder mounted to said guide rails for reciprocal movement therealong; and   said driving rack is connected to said fluid cylinder.   
     
     
       6. The box blank holding device as set forth in claim 1, wherein: each said holding member comprises a flat holding portion and a base portion extending substantially perpendicularly thereto, said base portion having a pivot connection adjacent said flat holding portion for pivotally mounting said holding member to its respective said holding-member actuating rack and a shaft mounting a said roller for engagement with said guide groove.   
     
     
       7. A box blank holding device for a box-making machine, comprising: a main body;   a driving rack;   motor means for reciprocally moving said driving rack relative to said main body;   a transmission shaft rotatably supported on said main body, said transmission shaft having a pair of pinions, one of said pinions being in meshing engagement with said driving rack;   a pair of holding-member actuating racks disposed in meshing engagement with the other said pinion;   each said holding-member actuating rack having a holding member pivotally mounted on an end thereof, whereby said holding members are movable with said holding-member actuating racks, said holding-member actuating racks being moved by said motor means reciprocally moving said driving rack to turn said one of said pinions, thus turning said other of said pinions and moving said holding-member actuating racks; and   means for pivotally moving said holding members between a projecting engagement position and a retracted position in response to movement of said holding-member actuating racks by said motor means.   
     
     
       8. The box blank holding device as set forth in claim 7, wherein: said main body has a front face, along which said holding-member actuating racks move, and upper and lower ends; and   said means for pivotally moving moves said holding members to their retracted position when said holding-member actuating racks move said holding members to said upper and lower ends of said main body.